The present invention relates to product checkout devices and more specifically to produce recognition system and method including weighted rankings.
Bar code readers are well known for their usefulness in retail checkout and inventory control. Bar code readers are capable of identifying and recording most items during a typical transaction since most items are labeled with bar codes.
Items which are typically not identified and recorded by a bar code reader are produce items, since produce items are typically not labeled with bar codes. Bar code readers may include a scale for weighing produce items to assist in determining the price of such items. But identification of produce items is still a task for the checkout operator, who must identify a produce item and then manually enter an item identification code. Operator identification methods are slow and inefficient because they typically involve a visual comparison of a produce item with pictures of produce items, or a lookup of text in table. Operator identification methods are also prone to error, on the order of fifteen percent.
A produce recognition system is disclosed in the cited co-pending application. A produce item is placed over a window in a spectral data collector, the produce item is illuminated, and the spectrum of the diffuse reflected light from the produce item is measured. A terminal compares the spectrum to reference spectra in a library. The terminal determines candidate produce items and corresponding ranks or confidence levels and chooses the candidate with the highest confidence level. The terminal additionally displays a number of candidates for operator verification and selection. The positions of the candidates are rank ordered.
However, a reference spectral waveform may not always be a unique reproducible signature of a produce item. Therefore, the terminal may not determine the same rank or even display a correct candidate each time the produce item is subjected to data collection.
Therefore, it would be desirable to supplement rankings based upon spectral analysis with information derived from limitations of using only spectral data.
In accordance with the teachings of the present invention, produce recognition system and method including weighted rankings is provided.
A produce recognition system and method which uses weighted rankings to increase the possibility that candidate identifications for a produce item will appear in the first-displayed screen of candidate identifications, rather than later screens accessed through operator scrolling. The system in includes a produce data collector which collects produce data for a produce item, and a computer system which compares the produce data to reference produce data to obtain a list of candidate identifications with first rankings based upon probability of match, determining weights for the candidate identifications based upon numbers of times the candidate identifications were correct identifications and were displayed in predetermined operator selection screen locations during past recognition events, applies the weights to the candidate identifications to obtain second rankings, displays the candidate identifications in order of the second rankings, and records an operator selection of one of the candidate identifications.
The method includes the steps of collecting produce data from the produce item, comparing the produce data to reference produce data to obtain a list of candidate identifications with first rankings based upon probability of match, determining weights for the candidate identifications based upon numbers of times the candidate identifications were correct identifications and were displayed in predetermined operator selection screen locations during past recognition events, applying the weights to the candidate identifications to obtain second rankings, displaying the candidate identifications in order of the second rankings, and recording an operator selection of one of the candidate identifications.
It is accordingly an object of the present invention to provide produce recognition system and method including weighted rankings.
It is another object of the present invention to improve the speed and accuracy of produce recognition.
It is another object of the present invention to augment produce data with additional data derived from inherent limitations of using the produce data to recognize produce items.
It is another object of the present invention to augment spectral data with additional data derived from inherent limitations of using the spectral data to recognize produce items.
It is another object of the present invention to increase the possibility that a candidate identification for a produce item will appear on a first-displayed candidate identification screen.